<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        var str1 = 'hello jS';
        var str2 = new String('hello');
        console.log(str1.toLowerCase());
        console.log(str1.toUpperCase());
        console.log(str1.length);//8

        var str3 = 'Hello JS and Java';
        console.log(str3.indexOf('J'));//6
        console.log(str3.indexOf('JS'));//6
        console.log(str3.indexOf('JS', 9));//-1

         var str4 = 'how are you doing today';
         var array = str4.split(' ');
         console.log(array);//['how', 'are', 'you', 'doing', 'today']
         console.log(array[2]);
    </script>
</body>
</html>